Friday, April 22, 2016

No association between HIV status and risk of non-fatal overdose among people who inject drugs in Vancouver, Canada

BACKGROUND:

The
evidence to date on whether HIV infection increases the risk of accidental drug
overdose among people who inject drugs (PWID) is equivocal. Thus, we sought to
estimate the effect of HIV infection on risk of non-fatal overdose among two
parallel cohorts of HIV-positive and -negative PWID.

METHODS:

Data were
collected from a prospective cohort of PWID in Vancouver, Canada between 2006
and 2013. During biannual follow-up assessments, non-fatal overdose within the
previous 6months was assessed. Bivariable and multivariable generalized
mixed-effects regression models were used to determine the unadjusted and
adjusted associations between HIV status, plasma HIV-1 RNA viral load, and
likelihood of non-fatal overdose.

RESULTS:

A total
of 1760 eligible participants (67% male, median age=42, and 42% HIV-positive at
baseline) were included. Among 15,070 unique observations, 649 (4.3%) included
a report of a non-fatal overdose within the previous 6months (4.4% among
seropositive and 4.3% among seronegative individuals). We did not observe a
difference in the likelihood of overdose by HIV serostatus in crude (odds ratio
[OR]: 1.05, p=0.853) analyses or analyses adjusted for known overdose risk
factors (adjusted OR [AOR]: 1.19, p=0.474). In a secondary analysis, among
HIV-positive PWID, we did not observe an association between having a
detectable viral load and overdose (AOR: 1.03, p=0.862).

CONCLUSIONS:

Despite
the evidence that HIV infection is a risk factor for fatal overdose, we found
no evidence for a relationship between HIV disease and non-fatal overdose.
However, overdose remains high among PWID, indicating the need for ongoing
policy addressing this problem, and research into understanding modifiable risk
factors that predict non-fatal overdose.